The principle of catalytic oxidation reaction of acetaldehyde

Principle of catalytic oxidation reaction of acetaldehyde:

Traditional acetaldehyde oxidation method of acetic acid, is a dissolved cobalt acetate, copper acetate or manganese acetate (generally 0.1%) as a catalyst, at 50 ~ 80 ℃, 0.6 ~ 0.8MPa, the acetic acid solution contained in 5% ~ 15% of the acetaldehyde for air or oxygen liquid-phase oxidation reaction.

It is generally believed that in the oxidation reaction of acetaldehyde, first of all, acetaldehyde and air (or oxygen) oxidation into peroxyacetic acid, peroxyacetic acid is very unstable, manganese acetate or copper acetate, cobalt acetate and other metal salts catalyzed decomposition occurs, and at the same time to make the oxidation of another molecule of acetaldehyde, generating two molecules of acetic acid. The oxidation reaction is exothermic.

The reaction mechanism of the oxidation of acetaldehyde to acetic acid is generally considered to be explained by the mechanism of the linkage reaction of free radicals. Acetaldehyde can be oxidized to form peroxyacetic acid at room temperature by automatically absorbing oxygen from the air at a very slow rate.

The free radical triggers a series of reactions to form acetic acid. During the reaction, peroxyacetic acid is a very unstable explosive compound, accumulated to a certain concentration will instantly decompose and cause an explosion.

Therefore, preventing the explosion caused by the accumulation of peroxyacetic acid is one of the keys to the acetic acid process of acetaldehyde oxidation. The main role of manganese acetate catalyst: the oxidation of acetaldehyde generated when the decomposition of peroxyacetic acid into acetic acid in a timely manner, while preventing the accumulation of peroxyacetic acid.

Extended information

Reaction of acetaldehyde:

1, industrial acetaldehyde equation: 2CH?CH?OH+O?→ 2CH?CHO+2H?O (heating, catalyst Cu/Ag)

2, acetylene hydration: C?H?+H?O→CH?CHO(). catalyst, heating) (is an addition reaction, but also a reduction reaction)

3, ethylene oxidation: 2CH?=CH?+O?→2CH?CHO (catalyst, heating, pressurization)

4, acetaldehyde catalytic oxidation: 2CH?CHO+O? →2CH?COOH (catalyst, heating)

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